The photolytic Conversion of energy derived from light is a common means in nature to drive chemical reactions. As an example, photosynthesis utilizes energy derived from sunlight to drive key metabolic processes in plants, while exchanging oxygen for carbon dioxide. The broad purpose of the proposed research is to apply principals of photolytic chemistry to create a novel family of photo-activated materials. In the current application, we will apply these fundamental concepts to study the feasibility of a photolytic artificial lung. It is notable that despite vast improvements across the spectrum of health care in the past 20 years, there have been few substantial improvements in the care of patients with end-stage lung disease. While the death rate for cardiovascular disease, cancer, and all other major diseases, has decreased significantly, the rate of death related to chronic lung disease has actually increased during this period. For these patients, long-term mechanical support of ventilation represents the only viable option to sustain life. As a result, there has long been interest in the development of technology to allow an exchange of oxygen for carbon dioxide, in the absence of normal lungs. The purpose of the current Phase I proposal will be to determine the optimum design and properties of a first generation photolytic surface, in terms of its materials, methods of photo-activation, and blood flow properties. In subsequent proposals, we will construct and validate a prototype photolytic module, then compile multiple such modules, in series with sensors, blood pumps, and control systems, to create a complete artificial lung device. Our aims for this Phase I proposal include: Specific Aim 1: The enhancement of photochemical yield by the development of improved photolytic coatings, system geometry, and light source. Specific Aim 2: The design and fabrication of a prototype photolytic surface, incorporating the results of material optimization and fluid dynamics modeling. The key milestones to be achieved during the current proposal include: the identification of photolytic coatings with the most efficient production of dissolved oxygen, the fabrication of a prototype flow through photolytic cell, and the elaboration of a model-based design for a high-yield photolytic module. It is anticipated that the successful implementation of this device in the clinical arena will have significant impact on the morbidity, mortality, and quality of life for the large number of children and adults with respiratory failure, as well as establishing an innovative realm of biomedical technology.